And boston



(No Model.)

. A. W. PEARSALL. VALVE-FOR PNEUMATIC DESPATGH TUBE SYSTEMS.

, No. 551,601. Patentd Dec. 17, 1895.

2o pointed out in .the claims.

' UNITED STAT S ATENT F 3 ALBERT W. PEARSALL, OF NEWV YORK, N. Y.,ASSIGNOR TO THE METEOR DESPATOH COMPANY, OF PORTLAND, MAINE, AND BOSTON,MASSACHU- SETTS.

VALVE FOR PNEUMATIIQ-DIISPATCH-TUBE SYSTEMS.

srncrrrcnrron forming'part of Letters Patent No. 551,601, dated December17, 1895.

Application filed October 15, 1894.

To aZZ whom itmay concern:

Be it known that I, ALBERT W; PEARSALL,

of New York, county of New York, and State of New York, have inventednew and useful 5 Improvements in Valves for Pneumatic-Dispatch-Tube'Systems and I hereby declare that the following is afull, clear, andexact description of the invention, which will enable others skilledin-the art to which it apro pertains to make and use the same.

My invention relates to certain newand useful improvements invacuum-valves for terminals in pneumatic e dispatchtube systerms inwhich the carriers are propelled by I 5 suction-i. 6., by withdrawingthepressure from the front of'the carrier as it travels through thesystem; and it consists of certain novel features, arrangements, andcombinations hereinafter described, and particularly In the drawings,Figure 1 represents a perspectiveview of the terminal at the salesmansstation. Figl 2 is a side view of the interior of the terminal with oneof the sides A removed. a 7 7 In the drawings like letters of referencere for to like parts.

The terminal A, which is known in the art as an upward discha'rgeterminal and can be used at either the cashiers or the salesmensstations, consists of an outer curved guidingwall A andflat sides A andwith flat bottom A so that it presents to the view a'box of an oval formcurved on top and with a flat bot- 3 5 tom. There is provided on theinside of this box a curved guiding-wall A which may be cast orotherwise secured to the sides A of the box, or it maybe 'cast orotherwise secured to the bottom WallA of the terminal, 40 and it extendsaround in the arc of a circle and terminates a short distance above thebottom wall 'of the terminal, and with the outer curved wall A it formsbetween them for the carriers a passage A which is a continuation of theinlet-tube B, through which the carriers are sent'to the terminal, andit is secured to the bottom. wall'A of the terminal between the outerwall A and'the inner wall A so that the carrier on entering the termi 5onal passes up between the side walls and Serial No. 525,877 (No model.)

around the passage A forming a continuation of the tube B, to the valve0 at the bottom of the terminal, which is opened by the impact of thecarrier as it passes from the inlet-tube B around the passage A to saidvalve, and the air-current passes under the lower end of the wall A intothe return suction-tube D, through which the carriers are returned, andthis keeps up a continuous aircurrent in the system.

a The valve '0 consists of two leaves 0 and O mounted fast on the shaft0 whichis journaled in the lower sides of the terminal. Below the leafOtthere is located a movable slide 0 by which the area of the bottom of6 3 the leaf O exposed to the atmospheric pressure can be increased ordecreased, as desired. The other leaf, C ,'of'the valve fits closely inthe bottom wall of the terminal and is' exposed on its upper surface tothe suction of the system and on its lower surfacelto the atmospheriopressure, and with this leaf 0 the carrier drawn through the systemimpacts and opens the valve and permits its discharge from the terminal.The carrier A coming through the passage A opens said valve by itsimpact with the leaf 0?, and the valve assumes the position shownindotted lines, Fig.

2, as the'carrier is delivered from the terminal, with the leaf C raisedup and contacting with the inner side of the inner wall A and thusclosing the air-passage under the wall A between the passage A and thereturn suction-tube D, which is secured to the bottom wall of theterminal.

As soon as the carrier passes from the terminal and past the leaf C theair-current between the passage A and the suction-tube D on the top sideof the leaf 0* forces said leaf back to its normal position and thuscloses the terminal to the atmosphere, and the air-currentcontinuesthrough the tube B, terminal A and return suction-tube D.

' A preferable construction of the terminal consists in casting the samein 'two upright 5 parts, which are firmly held together by bolts E,passing through and secured in the side walls A Supposing this terminalis located at the salesmans'station and it is desired to return thecarrier to the salesman from whom' it was sent, it is placed in thebranch tube 1*, connected with the return-tube D, and said branch tube Fis covered by a self-closing clapper F, hinged at W, and at this pointprovided with a projection F which limits the upward throw fof theclapper, and on its opposite side with a projection F by which theclapper is raised by the hand to permit the insertion of the carrier,and after the carrier has been pushed in the clapper is drawn to itsseat and held closed by the suction in the system.

As will be seen from the drawings, the bottom wall A fits under a partof the bottom of the leaf 0* and thus reduces the area of the bottomsurface of that leaf exposed to atmospheric pressure, and under thecenter part of the leaf 0 there moves a slide 0 on the tongue 0, andclosely fitting against the bottom of the said leaf to prevent access ofair to that part of the bottom surface of the leaf with which theslideis in contact, so that the extent of area of the leaf C exposed toatmospheric pressure can be regulated.

As the area of the bottom of the leaf 0" exposed to atmospheric pressureis less than the area of the bottom of the leaf C exposed to the saidatmospheric pressure, the difference in amount of pressure on the bottomof the two leaves of the valve will hold the said valve 0 suflieientlytight against the sides of the terminal, thus preventing any leakage,and at the same time make it easy for the carrier to operate the leaf Cof the valve. If none of the bottom surfaces of the leaf 0* were exposedto atmospheric pressure it would be diflicult for the carriers to openthe valve by their impact with the top of the leaf C, but the provisionby which the atmospheric pressure is admitted to a less area on thebottom of the leaf 0 than on the bottom of the leaf C not only holds thevalve closed to its seat but at the same time permits the easy operationof the valve by the impact of the carrier on the top of the leaf C It isobvious that if the above arrangement were not provided to produce adifference of area of the bottom of the leaves exposed to atmosphericpressure and the area exposed to atmospheric pressure on both leaves wasthe same there would be produced an exact balance which would not holdthe valve closed to its seat and which would swing more or less in theopening in which it was pivoted.

The main object, therefore, of my invention is to provide an arrangementby which the area, exposed to atmospheric pressure, of the bottomsurface of the leaf of the valve with which the carrier impacts isgreater than the area exposed to atmospheric pressure of the bottom ofthe opposite leaf.

By the provision of the movable slide G the area of the bottom of theleaf 0* exposed to atmospheric pressure may be increased to overcome theincreased pressure on the delivery side of the valve, due to theincreased friction of a long line thereby enabling the carrierdispatched on a long line to be deli vered as easily as one dispatchedon a short line.

Of course it will be understood that the construction shown simplyillustrates one manner of carrying out my invention, as it is obviousthat other constructions could be adopted which would embody the mainprinciple of my invention.

I do not limit myself to the exact arrange ment and construction shown,as the same may be varied without departing from the spirit of myinvention.

Having thus ascertained the nature and set forth the construction of myinvention, what I claim as new, and desire to secure by Letters Patent,is-

1. In a pneumatic dispatch tube system, the combination with a terminalhaving an. opening for the discharge of carriers, of a valve consistingof two leaves and normally closing said opening,and adapted to be openedby the impact of the carriers with one of said leaves, the atmosphericpressure on said leaf with which the carrier impacts tending to hold thevalve closed, and the atmospheric pressure on the other leaf tending toopen the valve.

2. In a pneumatic dispatch tube system, the combination with a terminalhaving an opening for the discharge of carriers, of a valve consistingof two leaves having different areas of surface exposed to atmosphericpressure and normally closing said opening and adapted to be opened bythe impact of the carriers with the lea-f having the greater area ofsurface exposed to atmospheric pressure, the atmospheric pressure on theleaf with which the carriers impact tending to hold the valve closed,and the atmospheric pressure on the other leaf tending to open thevalve.

In a pneumatic dispatch tube system, the combination with a terminalhaving an opening for the discharge of carriers, of a valve consistingof two leaves and normally closing said opening and adapted to be openedby the impact of the carriers with one of said leaves, the atmosphericpressure on the leaf with which the carriers impact tending to hold thevalve closed, and the atmospheric pressure on the other leaf tending toopen the valve, and means for varying'the area of exposed surface of thelatter leaf.

4:. In a pneumatic dispatch tube system, the combination with a terminalhaving an opening for the discharge of carriers, of a valve consistingof two leaves having different areas of surface exposed to'atl'nosphericpressure and normally closing said opening and adapted to be opened bythe impact of the carriers with the leaf having the greater area ofsurface exposed to atmospheric pressure, the atmospheric pressure on.the leaf with which; the carriers impact tending to two subscribingWitnesses, on this 3d day of hold the Valve closed, and the atmosphericOctober, 1894. pressure on the other leaf tending to open the valve, andmeans for varying the area of eX- ALBERT PEARSALL' 5 posed surface ofthe latter leaf. Witnesses:

In testimony whereof I have signed my A, S, TEMPLE,

name to this specification, in the presence of S. H. TROW.

